I need to work on the speed of my serve, I usually hit a kick that probably goes anywhere from 40-60mph and it lands in nearly 80% of the time. My accuracy isn’t where I’d like it to be either. My winners are usually of the mark by a couple inches and not as fast as I’d like to them. Got pretty decent court speed but it could always be better. I use the Cortex AeroPro Drive from Babolat currently but will probably have the GT within the week.
Any drills or exercises I could do to improve any aspect of my game would be helpful, especially if I could do them without a partner. Also any literature or videos you know that might help me would be appreciated too.
Thanks 
Also any recommendations on strings for when I get the GT
